Athens: Greece votes Sunday in a snap general election that could bring the radical left Syriza party to power and pose the most severe challenge yet to austerity policies in struggling eurozone countries.

Electing Syriza and their 40-year-old leader Alexis Tsipras would represent a leap into the unknown, but many Greeks appear prepared to take a chance after years of hardship.

Tsipras wants to renegotiate Greece`s massive 318 billion euro ($356 billion) debt and end the wage cuts and public spending reductions linked to an international bailout.

The possibility of a Syriza victory has sparked fears Greece could default on its debt repayments and quit the group of 19 countries using the single European currency in a so-called "Grexit".

Syriza lead the incumbent conservative New Democracy party of Prime Minister Antonis Samaras by at least four points heading into the election, according to the latest estimations.

Polling stations open at 0500 GMT and close at 1700 GMT, with the results from exit polls expected immediately after voting ends. Around 9.8 million Greeks are eligible to vote.

Tsipras has pledged to restore "dignity" to Greece and confront the so-called troika -- the European Union, International Monetary Fund (IMF) and European Central Bank (ECB) -- which imposed the conditions linked to a 240-billion-euro bailout deal.

The Syriza leader says Greece has been put in an "unsustainable" position, forced to make spiralling debt repayments while the economy shrinks.

The IMF, meanwhile, has warned Greece that failure to repay its debts will carry "consequences".

German Chancellor Angela Merkel, who is seen as being behind the EU`s austerity drive, said she hoped Greece would remain in the eurozone.

"I want Greece, despite the difficulties, to remain part of our story," she said Friday.

Greece, the host nation of the 2004 Summer Olympics, has seen a rapid economic decline since the eurozone crisis began, pushing unemployment up beyond 25 percent.Samaras argues it would be disastrous if voters bring Syriza to power just as the fiscal reforms he has supported could be about to bear fruit.

The 63-year-old Harvard-educated prime minister came to power after back-to-back elections in 2012 that routed the once-mighty Pasok socialist party.

Samaras initially argued for an easing of the terms of the bailout, but once in office he agreed to implement the deep cuts demanded by creditors.

He took a gamble last December by attempting to push forward a presidential election, but when lawmakers failed to agree on a candidate he was forced to call parliamentary elections.

Tsipras, a middle-class boy from Athens who trained as a civil engineer, says Syriza wants to smash the "oligarchy" that has traditionally dominated Greek politics and the media.

A Syriza official told AFP on Saturday the party was confident of victory. If it fails to gain the 151 parliamentary seats needed for an absolute majority it believes it would have little difficulty in forming a coalition government, the official said.

"Polls show we are five to 10 points ahead of New Democracy. What remains to be seen is whether we will have a clear majority," he added.

A likely coalition partner is To Potami (The River), a pro-European party founded last year by high-profile investigative journalist Stavros Theodorakis, which is polling at around six percent.

Tsipras has said he wants to reach a new settlement on the debt with the ECB by July, and intends to slash the amount by half.

Evdokia Kasoli, a pensioner in central Athens, expressed doubts on Saturday over whether Syriza would be able to keep their pledges.

"Tsipras is presentable, personable and a sweet-talker. But what can he achieve in the situation we`re now in?," she said.

A victory for Syriza could pave the way for other anti-austerity parties to break through in Europe. The leader of Spain`s radical Podemos movement, Pablo Iglesias, appeared with Tsipras at his final campaign rally in Athens on Thursday.